1. Field of the Invention
The invention relates generally to a method and apparatus for processing wafer-shaped articles, such as semiconductor wafers, in a closed process chamber.
2. Description of Related Art
Semiconductor wafers are subjected to various surface treatment processes such as etching, cleaning, polishing and material deposition. To accommodate such processes, a single wafer may be supported in relation to one or more treatment fluid nozzles by a chuck associated with a rotatable carrier, as is described for example in U.S. Pat. Nos. 4,903,717 and 5,513,668.
Alternatively, a chuck in the form of a ring rotor adapted to support a wafer may be located within a closed process chamber and driven without physical contact through an active magnetic bearing, as is described for example in International Publication No. WO 2007/101764 and U.S. Pat. No. 6,485,531. Treatment fluids which are driven outwardly from the edge of a rotating wafer due to centrifugal action are delivered to a common drain for disposal.
Although many methods and apparatus for single wafer wet processing are known, it remains a difficult problem to strip photoresist from semiconductor wafers, especially when the photoresist is deeply implanted with ions such as boron and arsenic. Most such methods require the use of large volumes of concentrated sulfuric acid, which is a relatively expensive process chemical, and one that is moreover impractical to recycle.